Fix example program

[baalexander]

When running node example/client-server.js, some of the getters are called before the setters. For example, getArray returns null even though setArray is called before with a value.

Putting the getArray code in the callback for the setArray ended up with the callback never getting called. It's possible the callback was never getting called.

// Nest the getter in the callback of the setter (getter does not currently get called)
client.methodCall('setArray', [['value1', 'value2']], function (error, value) {
  client.methodCall('getArray', null, function (error, value) {
    console.log('Get Array Response: ' + value)
  })
})